If your hands get as freezing cold as mine do in the winter months, you might be interested in these KARECEL Hand Warmers. They come with portable USB chargers, batteries, and even serve as backup batteries when needed. There are different temperature settings so you can enjoy just a bit of heat when needed or truly get toasty if you're super cold.
The shockproof warmer is also safe for use, shock-resistant and safeguarded by a protection system that keeps it from overloading on you. It's a much more affordable option than repeatedly buying single-use products that you have to throw away after using. It's also small enough to slip in your pocket and just keep your hands cozy there.
How do you stay warm in the winter months? Any special products that you like in particular? Share them in the chat!